Evaluation of the Cytotoxicity of Two Types of Triple Antibiotic Paste on Human Permanent Dental Apical Papilla Stem Cells: an in vitroin vitro Study

Statement of the Problem

The use of a new antimicrobial combination in the regenerative endodontic treatment of immature teeth pulp necrosis is a well-known method. Concerns have been raised about the destructive effect of this combination on the stem cells from the apical papilla of permanent human teeth, and there is a study gap.

Purpose

The main objective of the present study was to investigate the cytotoxic effect of modified triple antibiotic paste (mTAP) on stem cells from the apical papilla (SCAPs) of permanent human teeth.

Materials and Method

In this in vitro study, stem cells were removed from the immature teeth. After cultivation and third passage, metronidazole, ciprofloxacin, minocycline, and clindamycin were placed in the cell culture medium alone , paired, and in combinations as triple antibiotic paste (TAP) (metronidazole, ciprofloxacin, and minocycline) and mTAP (metronidazole, ciprofloxacin, clindamycin) with doses of 25, 50, 100, 200, 400μg/ml. After 1 and 3 days, cell viability in the culture medium was assessed using the MTT method ([4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). SPSS software version 24, descriptive statistics methods, and statistical tests such as Kruskal-Wallis and Mann-Whitney tests were adopted to analyze the data.

Results

Analysis of MTT findings indicated that the use of mTAP at 100μg/ml and TAP at 200μg/ml had no adverse cytotoxic effect on stem cells in the first 24 hours, compared to the control group. The cell viability decreased at higher concentrations, although it was not statistically significant. After 72 hours, the toxicity of concentrations higher than 100μg/ml of mTAP and 400 μg/ml of TAP significantly mitigated the percentage of viable cells.

Conclusion

The obtained results demonstrated that the concentration of 100 μg/ml of mTAP could replace TAP in regenerative endodontic treatments at the studied time intervals without worrying about the toxicity.

Evaluation effect of color in dental office and dentist's uniform while using two different distraction techniques on injection anxiety of 6-9 years' old children referring to Hamedan Dental School: Randomized clinical trial

Background:

The management of children's anxiety in dental offices is still a challenge for the treatment team. The most important factors which affect children's dental anxiety are the clinician-related factors and the physical factors of the dental operatory. Color is an environmental factor whose relationship with the perceptive and emotional factors of children has been reported. On the other hand, distraction is essential factors in a treatment environment that can be used to manage children's anxiety.

Materials and Methods:

In this randomized clinical trial study, from 132 6 to 9 years of age children, 52.3% were male, and 47.7% were female, with a mean age of 7.45 ± 1.1 years. The children's anxiety levels were determined using the Venham Picture Test and pulse oximetry before and after the administration of local anesthesia. The children were randomly assigned to two groups (n = 66): Group 1, music, and Group 2, animated cartoons. The data were analyzed with SPSS 25, using descriptive statistics and the statistical tests consisting of one-way analysis of variance (ANOVA), t-test, and repeated-measures ANOVA, followed by Tukey honestly significant difference tests. Statistical significance was set at P < 0.05.

Results:

The anxiety levels were the lowest in the blue and pink environments and the highest in the black and red. Anxiety levels between different colors in terms of physiologic markers and the questionnaire in each distraction technique at different intervals was significantly different.

Conclusion:

The use of blue, pink, green, and yellow for dentists' attire, and the interior design of the dental operatory decreased the child patients' anxiety.

Maximum equivalent stress induced and the displacement of the developing permanent first molars after the premature loss of primary second molars: A finite element analysis

BACKGROUND

The use of a space maintainer during the deciduous dentition period at a proper time can prevent the consequences of the loss of the arch length in the future. There is controversy over the use of space maintainers.

OBJECTIVES

The aim of this study was to evaluate the magnitude of stresses exerted on immature permanent molar teeth, and the extent of displacement of these teeth when the adjacent teeth are missing, but after placing a space maintainer. Studies carried out to date have used clinical measurements, e.g., X-rays and dental casts.

MATERIAL AND METHODS

The finite element model (FEM) was used for modeling the maxillary and mandibular teeth and the bone structure. A space maintainer (band and loop) was also designed for modeling. Force was applied and a finite element analysis (FEA) was carried out in 6 states in the maxilla and in the mandible to evaluate the distribution of stresses and the amount of displacement of immature permanent first molar teeth in the presence or absence of deciduous second molar teeth and a space maintainer.

RESULTS

During mastication, when the deciduous second molar tooth was absent, the maximum stress was transferred to incomplete roots. When there was a space maintainer, stress was transferred to the space maintainer itself and to the distal side of the deciduous first molar tooth. The displacement of permanent first molar teeth was minimal in the presence of all teeth; in the absence of the deciduous second molar tooth, this displacement increased 4-5-fold, which decreased again almost to the level of the 1st/4th state (intact arch) in the presence of the space maintainer.

CONCLUSIONS

The results showed the importance of the use of space maintainers, as they significantly decrease the momentary displacement of the teeth as well as the stress exerted on the developing permanent first molar teeth.

Effect of Calcium-enriched Mixture (CEM) cement on increasing mineralization in stem cells from the dental pulps of human exfoliated deciduous teeth

Background.Stem cells isolated from human exfoliated deciduous teeth (SHED) are highly capable of proliferation and differentiation into odontogenic, osteogenic, adipose tissue and neural cells. The aim of this study was to investigate the effect of CEM cement on increasing mineralization in stem cells of exfoliated deciduous teeth. Methods.Dental pulps were isolated from extracted exfoliating primary teeth and immersed in a digestive solution. The dental pulp cells were immersed in α-MEM (modified culture medium) and 10% fetal bovine serum (FBS) was added. The culture cells were used for mineral deposit formation after the third passage. The cells were cultured in osteogenic cell culture medium in the control group and in osteogenic culture medium supplemented with CEM cement in the case group. Alizarin red staining was used to evaluate the mineral deposit formation on day 21. Statistical significance was determined with t-test. Results.Quantification of alizarin red staining showed that cells exposed to CEM cement induced more mineralized nodules (P=0.03). Conclusion.Mineral deposit formation in SHEDs was stimulated by CEM cement. Based on these data it might be suggested that CEM could improve osteoblastic differentiation.

Effect of Calcium-enriched Mixture (CEM) cement on increasing mineralization in stem cells from the dental pulps of human exfoliated deciduous teeth

Background. Stem cells isolated from human exfoliated deciduous teeth (SHED) are highly capable of proliferation and differentiation into odontogenic, osteogenic, adipose tissue and neural cells. The aim of this study was to investigate the effect of CEM cement on increasing mineralization in stem cells of exfoliated deciduous teeth.

Methods. Dental pulps were isolated from extracted exfoliating primary teeth and immersed in a digestive solution. The dental pulp cells were immersed in α-MEM (modified culture medium) and 10% fetal bovine serum (FBS) was added. The culture cells were used for mineral deposit formation after the third passage. The cells were cultured in osteogenic cell culture medium in the control group and in osteogenic culture medium supplemented with CEM cement in the case group. Alizarin red staining was used to evaluate the mineral deposit formation on day 21. Statistical significance was determined with t-test.

Results. Quantification of alizarin red staining showed that cells exposed to CEM cement induced more mineralized nodules (P=0.03).

Conclusion. Mineral deposit formation in SHEDs was stimulated by CEM cement. Based on these data it might be suggested that CEM could improve osteoblastic differentiation.

The Effect of 1α,25(OH)2D3 on Osteogenic Differentiation of Stem Cells from Dental Pulp of Exfoliated Deciduous Teeth

STATEMENT OF THE PROBLEM

Stem cells from human exfoliated deciduous teeth (SHEDs) are a population of highly proliferative cells, being capable of differentiating into osteogenic, odontogenic, adipocytes, and neural cells. Vitamin D3 metabolites such as 1α, 25-dihydroxyvitamin D3 are key factors in the regulation of bone metabolism.

PURPOSE

The aim of this study was to investigate the effect of 1α, 25-dihydroxyvitamin D3 on osteogenic differentiation (alkaline phosphatase activity and alizarin red staining) of stem cells of exfoliated deciduous teeth.

MATERIALS AND METHOD

Dental pulp was removed from freshly extracted primary teeth and immersed in a digestive solution. Then, the dental pulp cells were immersed in α-MEM (minimum essential medium) to which 10% fetal bovine serum was added. After the third passage, the cells were isolated from the culture plate and were used for osteogenic differentiation. As a control group, the cells were cultured in osteogenic cell culture medium. As the case group, the cells were cultured in osteogenic culture medium supplemented with 100 nM 1α,25 (OH)2D3. The alkaline phosphatase (ALP) activity and alizarin red staining were analyzed to evaluate the osteogenic differentiation at day 21. The results were analyzed by using t-test.

RESULTS

Compared with the control group, significant increase was observed in ALP activity of SHEDs after being treated with 1α,25(OH)2D3 (p= 0.002). Alizarin red staining demonstrated that the cells exposed to 1α,25(OH)2D3 induced higher mineralized nodules (p< 0.001).

CONCLUSION

Osteoblast differentiation in SHEDs was stimulated by 1α,25(OH) 2D3. It can be concluded that 1α,25(OH)2D3 can improve osteoblastic differentiation.

A Multidisciplinary Approach to a Seven Year-Old Patient with Incontinentia Pigmenti: A Case Report and Five-Year Follow Up

Incontinentia pigmenti is a rare inherited disorder involving abnormalities of the skin, hair, eyes, musculoskeletal system, central nervous system, and the teeth. Dental abnormalities are the most common manifestations of this disorder. The purpose of this case report was to present the clinical and radiological findings of a seven-year-old girl as well as the results of her five-year follow up. The patient showed faded linear pigmented macular lesions on the trunk and on upper and lower limbs. Dental examination was notable for conical and peg-shaped anterior teeth as well as delayed eruption of primary and permanent teeth. In addition to conservative treatments, prosthetic treatments such as interim removable partial dentures were indicated for the patient.

Dental Health Status and Hygiene in Children and Adolescents with Type 1 Diabetes Mellitus

BACKGROUND

There is disagreement on the effect of diabetes on oral hygiene. The purpose of this study was to assess the oral health and hygiene status of type 1 diabetic patient.

METHODS

In this case control study, periodontal health and hygiene of 80 children and adolescents (5-18 yr of age) with type 1 diabetes mellitus referred to Pediatric Endocrine Clinic of Besat Hospital Hamadan Iran 2013 - 2014 and 80 non diabetic control subjects were clinically assessed. The required data such as sex, age, duration of the diabetes, type and number of insulin injections per day were obtained from self-administered questionnaire and the patient's medical records. Participants in both groups were examined for Decay-missing- filled teeth (DMFT); dmft (for primary teeth), oral hygiene using O'Leary plaque index (PI) and gingivitis index (GI). P<0.05 was considered significant.

RESULTS

The mean age of the study and the control group was 12.5±4.05 and 12.08±3.47 yr, respectively. There were no significant difference between two groups in terms of DMFT (P=0.158) and PI indices (P=0.373). The GI index difference was statistically significant in diabetic group (P=0.001). Interestingly, a higher dmft index was observed in the control group (P=0.008). In diabetic groups, GI and DMFT index increased significantly with duration of diabetes.

CONCLUSIONS

Apart from higher scores of GI index, frequency of oral and periodontal disease was not different in diabetic patients compared with healthy subjects. Findings of present study are insufficient to support a significant effect of diabetes on increasing the risk of oral and periodontal diseases. However, diabetic children and adolescents should receive oral hygiene instruction.